1. Field of the Invention
The present invention relates to an irradiation loading apparatus and to a method of irradiating a localized area using the inventive irradiation loading apparatus. The inventive irradiation loading apparatus is particularly suitable for the intrabronchial irradiation of a human patient
2. Description of Related Art
Fully automated remote control machines for treating human or animal patients by local irradiation at a high dose rate from a radioactive substance are known, for example, from U.S. Pat. No. 3,669,093 to Sauerwein at el. Such automated irradiation machines suffer from a number of significant disadvantages which have prohibited their widespread use.
Most significantly, fully automated remote control irradiation machines are extremely expensive to manufacture, maintain and operate. For example, a fully automated irradiation machine, such as that disclosed in U.S. Pat. No. 3,669,093, requires an initial expenditure of between about $300,000 and $500,000 and the annual maintenance and operating cost of such an automated machine is approximately $100,000.00. The cost of purchasing, operating and maintaining such an automated irradiation machine is so prohibitive that only large urban medical centers are capable of acquiring this automated irradiation machinery and thus patients in need of localized irradiation treatment have extremely limited access thereto.
In addition, the automated irradiation machines are completely immobile and must be used in a shielded lead room. The radiation exposure level surrounding the automated irradiation machine when it is in use is extremely high and the operator of the automated machine cannot be in the room in which the machine is being used to treat a patient.
Finally, the automated irradiation machines are complex and contain a number of complex moving parts that are susceptible to breakdown and cannot be actually observed by an operator while the automated irradiation machine is in operation. For example, the automated machine moves a radioactive source of 5 to 10 curies continually over lesions or areas to be treated, thus increasing the potential for unobserved breakdown.
A typical dose rate of radiation with the automated machine is between 500 and 1000 rads/minute. This high radiation dose rate level means that the potential exposure of operating personnel would be extremely high if operating personnel were to be present in the same room as the automated irradiation machine. Thus, a lead shielded room in which the operator cannot be present is necessary in order to use the automated irradiation machine to treat a patient.
Therefore, it is object of the present invention to provide an irradiation loading apparatus which does not suffer from the disadvantages of known irradiation machines.
It is further an object of the present invention to provide a simple, inexpensive and manually operated irradiation loading apparatus which would enable smaller medical centers to provide localized irradiation treatment to patients in need thereof.
It is yet another object of the present invention to provide an irradiation loading apparatus which is portable and can be transported to and operated in a patient's hospital room, utilizing portable shields.
It is still another object of the present invention to provide an irradiation loading apparatus which can be operated by an operator in the same room with portable shields and does not require operation in a specially designed or constructed shielded room.
Yet another object of the present invention is to provide an irradiation loading apparatus which supplies low dose rate radiation to a lesion of a patient resulting in normal tissue repair at a faster rate than that for high does rate irradiation.
Additional advantages and objects of the present invention will be apparent from the accompanying description and drawings wherein: